State-of-the-art integrated CO^sub 2^ refrigeration system for supermarkets: A comparative analysis

This paper investigates the integrated and state-of-the art features of CO2 trans-critical booster systems. The main objective is to identify the most promising solutions in terms of energy efficiency impacts.First, the performance of modified features and integrated functions have been compared with the standard CO2 system and alternative heating and air conditioning solutions. Subsequently, the performance of the defined state-of-the-art CO2 system is compared to natural refrigerant-based cascade and HFC/HFO-based DX and indirect refrigeration solutions operating in cold and warm climates.The results indicate that two-stage heat recovery, flooded evaporation, parallel compression and integration of air conditioning are the most promising features of the state-of-the-art integrated CO2 system. This compact and environmentally friendly system is the most energy efficient solution in cold climates, and is also an efficient solution in warm climates, with comparable efficiency to cascade and HFC/HFO DX systems, but with no existing or potential limitations.